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Diffstat (limited to 'fs/ext4/ext4_jbd2.h')
-rw-r--r-- | fs/ext4/ext4_jbd2.h | 399 |
1 files changed, 399 insertions, 0 deletions
diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h new file mode 100644 index 00000000..83b20fcf --- /dev/null +++ b/fs/ext4/ext4_jbd2.h @@ -0,0 +1,399 @@ +/* + * ext4_jbd2.h + * + * Written by Stephen C. Tweedie <sct@redhat.com>, 1999 + * + * Copyright 1998--1999 Red Hat corp --- All Rights Reserved + * + * This file is part of the Linux kernel and is made available under + * the terms of the GNU General Public License, version 2, or at your + * option, any later version, incorporated herein by reference. + * + * Ext4-specific journaling extensions. + */ + +#ifndef _EXT4_JBD2_H +#define _EXT4_JBD2_H + +#include <linux/fs.h> +#include <linux/jbd2.h> +#include "ext4.h" + +#define EXT4_JOURNAL(inode) (EXT4_SB((inode)->i_sb)->s_journal) + +/* Define the number of blocks we need to account to a transaction to + * modify one block of data. + * + * We may have to touch one inode, one bitmap buffer, up to three + * indirection blocks, the group and superblock summaries, and the data + * block to complete the transaction. + * + * For extents-enabled fs we may have to allocate and modify up to + * 5 levels of tree + root which are stored in the inode. */ + +#define EXT4_SINGLEDATA_TRANS_BLOCKS(sb) \ + (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS) \ + ? 27U : 8U) + +/* Extended attribute operations touch at most two data buffers, + * two bitmap buffers, and two group summaries, in addition to the inode + * and the superblock, which are already accounted for. */ + +#define EXT4_XATTR_TRANS_BLOCKS 6U + +/* Define the minimum size for a transaction which modifies data. This + * needs to take into account the fact that we may end up modifying two + * quota files too (one for the group, one for the user quota). The + * superblock only gets updated once, of course, so don't bother + * counting that again for the quota updates. */ + +#define EXT4_DATA_TRANS_BLOCKS(sb) (EXT4_SINGLEDATA_TRANS_BLOCKS(sb) + \ + EXT4_XATTR_TRANS_BLOCKS - 2 + \ + EXT4_MAXQUOTAS_TRANS_BLOCKS(sb)) + +/* + * Define the number of metadata blocks we need to account to modify data. + * + * This include super block, inode block, quota blocks and xattr blocks + */ +#define EXT4_META_TRANS_BLOCKS(sb) (EXT4_XATTR_TRANS_BLOCKS + \ + EXT4_MAXQUOTAS_TRANS_BLOCKS(sb)) + +/* Delete operations potentially hit one directory's namespace plus an + * entire inode, plus arbitrary amounts of bitmap/indirection data. Be + * generous. We can grow the delete transaction later if necessary. */ + +#define EXT4_DELETE_TRANS_BLOCKS(sb) (2 * EXT4_DATA_TRANS_BLOCKS(sb) + 64) + +/* Define an arbitrary limit for the amount of data we will anticipate + * writing to any given transaction. For unbounded transactions such as + * write(2) and truncate(2) we can write more than this, but we always + * start off at the maximum transaction size and grow the transaction + * optimistically as we go. */ + +#define EXT4_MAX_TRANS_DATA 64U + +/* We break up a large truncate or write transaction once the handle's + * buffer credits gets this low, we need either to extend the + * transaction or to start a new one. Reserve enough space here for + * inode, bitmap, superblock, group and indirection updates for at least + * one block, plus two quota updates. Quota allocations are not + * needed. */ + +#define EXT4_RESERVE_TRANS_BLOCKS 12U + +#define EXT4_INDEX_EXTRA_TRANS_BLOCKS 8 + +#ifdef CONFIG_QUOTA +/* Amount of blocks needed for quota update - we know that the structure was + * allocated so we need to update only data block */ +#define EXT4_QUOTA_TRANS_BLOCKS(sb) (test_opt(sb, QUOTA) ? 1 : 0) +/* Amount of blocks needed for quota insert/delete - we do some block writes + * but inode, sb and group updates are done only once */ +#define EXT4_QUOTA_INIT_BLOCKS(sb) (test_opt(sb, QUOTA) ? (DQUOT_INIT_ALLOC*\ + (EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)+3+DQUOT_INIT_REWRITE) : 0) + +#define EXT4_QUOTA_DEL_BLOCKS(sb) (test_opt(sb, QUOTA) ? (DQUOT_DEL_ALLOC*\ + (EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)+3+DQUOT_DEL_REWRITE) : 0) +#else +#define EXT4_QUOTA_TRANS_BLOCKS(sb) 0 +#define EXT4_QUOTA_INIT_BLOCKS(sb) 0 +#define EXT4_QUOTA_DEL_BLOCKS(sb) 0 +#endif +#define EXT4_MAXQUOTAS_TRANS_BLOCKS(sb) (MAXQUOTAS*EXT4_QUOTA_TRANS_BLOCKS(sb)) +#define EXT4_MAXQUOTAS_INIT_BLOCKS(sb) (MAXQUOTAS*EXT4_QUOTA_INIT_BLOCKS(sb)) +#define EXT4_MAXQUOTAS_DEL_BLOCKS(sb) (MAXQUOTAS*EXT4_QUOTA_DEL_BLOCKS(sb)) + +/** + * struct ext4_journal_cb_entry - Base structure for callback information. + * + * This struct is a 'seed' structure for a using with your own callback + * structs. If you are using callbacks you must allocate one of these + * or another struct of your own definition which has this struct + * as it's first element and pass it to ext4_journal_callback_add(). + */ +struct ext4_journal_cb_entry { + /* list information for other callbacks attached to the same handle */ + struct list_head jce_list; + + /* Function to call with this callback structure */ + void (*jce_func)(struct super_block *sb, + struct ext4_journal_cb_entry *jce, int error); + + /* user data goes here */ +}; + +/** + * ext4_journal_callback_add: add a function to call after transaction commit + * @handle: active journal transaction handle to register callback on + * @func: callback function to call after the transaction has committed: + * @sb: superblock of current filesystem for transaction + * @jce: returned journal callback data + * @rc: journal state at commit (0 = transaction committed properly) + * @jce: journal callback data (internal and function private data struct) + * + * The registered function will be called in the context of the journal thread + * after the transaction for which the handle was created has completed. + * + * No locks are held when the callback function is called, so it is safe to + * call blocking functions from within the callback, but the callback should + * not block or run for too long, or the filesystem will be blocked waiting for + * the next transaction to commit. No journaling functions can be used, or + * there is a risk of deadlock. + * + * There is no guaranteed calling order of multiple registered callbacks on + * the same transaction. + */ +static inline void ext4_journal_callback_add(handle_t *handle, + void (*func)(struct super_block *sb, + struct ext4_journal_cb_entry *jce, + int rc), + struct ext4_journal_cb_entry *jce) +{ + struct ext4_sb_info *sbi = + EXT4_SB(handle->h_transaction->t_journal->j_private); + + /* Add the jce to transaction's private list */ + jce->jce_func = func; + spin_lock(&sbi->s_md_lock); + list_add_tail(&jce->jce_list, &handle->h_transaction->t_private_list); + spin_unlock(&sbi->s_md_lock); +} + +/** + * ext4_journal_callback_del: delete a registered callback + * @handle: active journal transaction handle on which callback was registered + * @jce: registered journal callback entry to unregister + */ +static inline void ext4_journal_callback_del(handle_t *handle, + struct ext4_journal_cb_entry *jce) +{ + struct ext4_sb_info *sbi = + EXT4_SB(handle->h_transaction->t_journal->j_private); + + spin_lock(&sbi->s_md_lock); + list_del_init(&jce->jce_list); + spin_unlock(&sbi->s_md_lock); +} + +int +ext4_mark_iloc_dirty(handle_t *handle, + struct inode *inode, + struct ext4_iloc *iloc); + +/* + * On success, We end up with an outstanding reference count against + * iloc->bh. This _must_ be cleaned up later. + */ + +int ext4_reserve_inode_write(handle_t *handle, struct inode *inode, + struct ext4_iloc *iloc); + +int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode); + +/* + * Wrapper functions with which ext4 calls into JBD. + */ +void ext4_journal_abort_handle(const char *caller, unsigned int line, + const char *err_fn, + struct buffer_head *bh, handle_t *handle, int err); + +int __ext4_journal_get_write_access(const char *where, unsigned int line, + handle_t *handle, struct buffer_head *bh); + +int __ext4_forget(const char *where, unsigned int line, handle_t *handle, + int is_metadata, struct inode *inode, + struct buffer_head *bh, ext4_fsblk_t blocknr); + +int __ext4_journal_get_create_access(const char *where, unsigned int line, + handle_t *handle, struct buffer_head *bh); + +int __ext4_handle_dirty_metadata(const char *where, unsigned int line, + handle_t *handle, struct inode *inode, + struct buffer_head *bh); + +int __ext4_handle_dirty_super(const char *where, unsigned int line, + handle_t *handle, struct super_block *sb); + +#define ext4_journal_get_write_access(handle, bh) \ + __ext4_journal_get_write_access(__func__, __LINE__, (handle), (bh)) +#define ext4_forget(handle, is_metadata, inode, bh, block_nr) \ + __ext4_forget(__func__, __LINE__, (handle), (is_metadata), (inode), \ + (bh), (block_nr)) +#define ext4_journal_get_create_access(handle, bh) \ + __ext4_journal_get_create_access(__func__, __LINE__, (handle), (bh)) +#define ext4_handle_dirty_metadata(handle, inode, bh) \ + __ext4_handle_dirty_metadata(__func__, __LINE__, (handle), (inode), \ + (bh)) +#define ext4_handle_dirty_super(handle, sb) \ + __ext4_handle_dirty_super(__func__, __LINE__, (handle), (sb)) + +handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks); +int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle); + +#define EXT4_NOJOURNAL_MAX_REF_COUNT ((unsigned long) 4096) + +/* Note: Do not use this for NULL handles. This is only to determine if + * a properly allocated handle is using a journal or not. */ +static inline int ext4_handle_valid(handle_t *handle) +{ + if ((unsigned long)handle < EXT4_NOJOURNAL_MAX_REF_COUNT) + return 0; + return 1; +} + +static inline void ext4_handle_sync(handle_t *handle) +{ + if (ext4_handle_valid(handle)) + handle->h_sync = 1; +} + +static inline void ext4_handle_release_buffer(handle_t *handle, + struct buffer_head *bh) +{ + if (ext4_handle_valid(handle)) + jbd2_journal_release_buffer(handle, bh); +} + +static inline int ext4_handle_is_aborted(handle_t *handle) +{ + if (ext4_handle_valid(handle)) + return is_handle_aborted(handle); + return 0; +} + +static inline int ext4_handle_has_enough_credits(handle_t *handle, int needed) +{ + if (ext4_handle_valid(handle) && handle->h_buffer_credits < needed) + return 0; + return 1; +} + +static inline handle_t *ext4_journal_start(struct inode *inode, int nblocks) +{ + return ext4_journal_start_sb(inode->i_sb, nblocks); +} + +#define ext4_journal_stop(handle) \ + __ext4_journal_stop(__func__, __LINE__, (handle)) + +static inline handle_t *ext4_journal_current_handle(void) +{ + return journal_current_handle(); +} + +static inline int ext4_journal_extend(handle_t *handle, int nblocks) +{ + if (ext4_handle_valid(handle)) + return jbd2_journal_extend(handle, nblocks); + return 0; +} + +static inline int ext4_journal_restart(handle_t *handle, int nblocks) +{ + if (ext4_handle_valid(handle)) + return jbd2_journal_restart(handle, nblocks); + return 0; +} + +static inline int ext4_journal_blocks_per_page(struct inode *inode) +{ + if (EXT4_JOURNAL(inode) != NULL) + return jbd2_journal_blocks_per_page(inode); + return 0; +} + +static inline int ext4_journal_force_commit(journal_t *journal) +{ + if (journal) + return jbd2_journal_force_commit(journal); + return 0; +} + +static inline int ext4_jbd2_file_inode(handle_t *handle, struct inode *inode) +{ + if (ext4_handle_valid(handle)) + return jbd2_journal_file_inode(handle, EXT4_I(inode)->jinode); + return 0; +} + +static inline void ext4_update_inode_fsync_trans(handle_t *handle, + struct inode *inode, + int datasync) +{ + struct ext4_inode_info *ei = EXT4_I(inode); + + if (ext4_handle_valid(handle)) { + ei->i_sync_tid = handle->h_transaction->t_tid; + if (datasync) + ei->i_datasync_tid = handle->h_transaction->t_tid; + } +} + +/* super.c */ +int ext4_force_commit(struct super_block *sb); + +/* + * Ext4 inode journal modes + */ +#define EXT4_INODE_JOURNAL_DATA_MODE 0x01 /* journal data mode */ +#define EXT4_INODE_ORDERED_DATA_MODE 0x02 /* ordered data mode */ +#define EXT4_INODE_WRITEBACK_DATA_MODE 0x04 /* writeback data mode */ + +static inline int ext4_inode_journal_mode(struct inode *inode) +{ + if (EXT4_JOURNAL(inode) == NULL) + return EXT4_INODE_WRITEBACK_DATA_MODE; /* writeback */ + /* We do not support data journalling with delayed allocation */ + if (!S_ISREG(inode->i_mode) || + test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) + return EXT4_INODE_JOURNAL_DATA_MODE; /* journal data */ + if (ext4_test_inode_flag(inode, EXT4_INODE_JOURNAL_DATA) && + !test_opt(inode->i_sb, DELALLOC)) + return EXT4_INODE_JOURNAL_DATA_MODE; /* journal data */ + if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) + return EXT4_INODE_ORDERED_DATA_MODE; /* ordered */ + if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA) + return EXT4_INODE_WRITEBACK_DATA_MODE; /* writeback */ + else + BUG(); +} + +static inline int ext4_should_journal_data(struct inode *inode) +{ + return ext4_inode_journal_mode(inode) & EXT4_INODE_JOURNAL_DATA_MODE; +} + +static inline int ext4_should_order_data(struct inode *inode) +{ + return ext4_inode_journal_mode(inode) & EXT4_INODE_ORDERED_DATA_MODE; +} + +static inline int ext4_should_writeback_data(struct inode *inode) +{ + return ext4_inode_journal_mode(inode) & EXT4_INODE_WRITEBACK_DATA_MODE; +} + +/* + * This function controls whether or not we should try to go down the + * dioread_nolock code paths, which makes it safe to avoid taking + * i_mutex for direct I/O reads. This only works for extent-based + * files, and it doesn't work if data journaling is enabled, since the + * dioread_nolock code uses b_private to pass information back to the + * I/O completion handler, and this conflicts with the jbd's use of + * b_private. + */ +static inline int ext4_should_dioread_nolock(struct inode *inode) +{ + if (!test_opt(inode->i_sb, DIOREAD_NOLOCK)) + return 0; + if (!S_ISREG(inode->i_mode)) + return 0; + if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) + return 0; + if (ext4_should_journal_data(inode)) + return 0; + return 1; +} + +#endif /* _EXT4_JBD2_H */ |